title: Towards systems biology of heterosis: a hypothesis about molecular network structure applied for the Arabidopsis metabolome.
abstract: We propose a network structure-based model for heterosis, and investigate it relying on metabolite profiles from Arabidopsis. A simple feed-forward two-layer network model (the Steinbuch matrix) is used in our conceptual approach. It allows for directly relating structural network properties with biological function. Interpreting heterosis as increased adaptability, our model predicts that the biological networks involved show increasing connectivity of regulatory interactions. A detailed analysis of metabolite profile data reveals that the increasing-connectivity prediction is true for graphical Gaussian models in our data from early development. This mirrors properties of observed heterotic Arabidopsis phenotypes. Furthermore, the model predicts a limit for increasing hybrid vigor with increasing heterozygosity--a known phenomenon in the literature.
authors.affiliation: Bioinformatics and Biomathematics Group, Genetics and Biometry Unit, Research Institute for the Biology of Farm Animals, Wilhelm-Stahl Allee 2, Dummerstorf, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Andorf
authors.forename: Tanja
authors.initials: T
authors.lastname: Gärtner
authors.forename: Matthias
authors.initials: M
authors.lastname: Steinfath
authors.forename: Hanna
authors.initials: H
authors.lastname: Witucka-Wall
authors.forename: Thomas
authors.initials: T
authors.lastname: Altmann
authors.forename: Dirk
authors.initials: D
authors.lastname: Repsilber